1. Field of Invention
The present invention relates to a bicycle, and more particularly to a foldable bicycle comprising a triangular body frame which is capable of being folded into a compact structure.
2. Description of Related Arts
Since the first bicycle was invented, it has been widely utilized as an economical and convenient mode of transportation. With the advance of technology, bicycles have become a kind of leisure and sports equipment. Many people would ride bicycle occasionally and store it in a safe place while they are not using the bicycle.
Therefore, the bulky size of a conventional bicycle has caused many problems for many people, especially those who live in a confined apartment or in a city where space has become extremely valuable. In such cases, people have to worry where to store their bulky bicycles while they are not in use. While some of them may secure a place in their garages or somewhere outside their home, yet many of them have to put their bicycles into their apartments and suffer from much inconvenience. In some circumstances, the bulky bicycle may become a potential source of danger for children.
In order to resolve this problem, some sort of foldable bicycles have been developed in which the bicycle frame is adapted to be folded to form a compact structure so as to minimize the spatial requirement needed for storing the foldable bicycle. On the face, this idea sounds promising in that the foldable bicycles take much less space and people may store them conveniently without causing much difficulty.
There are, however, discrepancies among these foldable bicycles. A conventional foldable bicycle usually comprises a bicycle frame supporting two bicycle wheels and a user, wherein the bicycle frame comprises a front frame rotatably supporting the front wheel, a rear frame rotatably supporting the rear wheel, and a body supporting frame connecting between the front frame and the rear frame for supporting the user. The driving arrangement of the foldable bicycle is usually mounted on the body supporting frame for driving the foldable bicycle. Very often, the body supporting frame comprises one single longitudinal member connecting the front frame and the rear frame so that by mounting a folding joint at the longitudinal member, this longitudinal member is selectively detached into two portions for folding and unfolding with respect to a pivot.
It follows that since the body supporting frame is limited to comprising one single longitudinal member, the amount of which it can carry load is inevitably limited. Therefore, conventional foldable bicycles tend to be small in size, and only fit for a limited number of people, and for a limited number of circumstances.
As a matter of fact, there exist some other bicycles in which their body supporting frame comprises three supporting members each of which is integrally connected in an end to end manner with the adjacent one so as to form a triangular structure. In such a case, it is difficult to fold the triangular structure so as to fold the entire bicycle into a compact structure. It may be possible to mount a folding joint on each of the supporting members for folding and unfolding, but this poses a great risk of structure instability, especially when the bicycle is in the course of vigorous operation, such as in the course of climbing uphill.